Napolitano joined Defense Secretary Leon E. Panetta in the Pentagon Auditorium this morning for a change of responsibility ceremony to welcome Army Gen. Frank Grass as the new National Guard Bureau chief and to pay tribute to McKinley’s nearly 40 years of service.

Army Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, also was on the stage. The standing-room-only audience included Veterans Affairs Secretary Eric K. Shinseki, Joint Chiefs Vice Chairman Navy Adm. James A. Winnefeld Jr., Air Force Secretary Michael B. Donley, defense civilian and military leaders, senior enlisted members, National Guard state adjutants general, former Guard Bureau chiefs and international partners from many nations.

“Speaking as a former governor [of Arizona] who advocated for a strong National Guard chief,” Napolitano said, “I was heartened to see that General McKinley was not only the first four-star general to lead the National Guard, but also the first National Guard Bureau chief to sit on the Joint Chiefs of Staff.”

Among McKinley’s many responsibilities, she added, is to ensure that more than a half-million National Guard personnel are accessible, capable and ready to protect the homeland and to provide combat resources to the Army and Air Force.

“His leadership has been instrumental in helping build the strong relationships that we have today among our many federal, state, local, tribal, territorial and foreign partners,” Napolitano noted.

Homeland Security has worked with the National Guard Bureau and partners on the ground for more than a decade, the secretary said, adding that she’s proud of recent progress in two areas: improving the nation’s disaster response capabilities and strengthening security along the nation’s southwest border.

McKinley and the National Guard have been essential partners in both successes, Napolitano said.

“To improve our coordination and better prepare for and respond to disasters, he embraced a whole-of-government approach, drawing on leadership and resources from all levels,” she added.

McKinley worked closely with the U.S. Council of Governors and with Congress to implement the Dual-status Commander Initiative, she added, which streamlines operations while respecting the National Guard’s responsibilities to home states and the federal government.

The dual-status command allows a National Guard officer or a commissioned federal military officer to simultaneously direct state and federal military forces, according to National Governors Association officials. The appointment requires presidential authorization and approval by the affected governor, officials said, adding that while state and federal forces remain separate and distinct, the appointment authorizes the dual-status commander to direct the operations of all forces.

“The National Guard has also strongly supported [the Federal Emergency Management Agency’s] contingency response exercises, making sure we are ready to respond together whenever we are called,” Napolitano said. “And indeed, we have been called on again and again and again and again.”

Even before Hurricane Isaac came ashore in south Florida and into Louisiana and the Middle Mississippi Valley, the National Guard began mobilizing, the secretary said, ultimately deploying more than 6,000 soldiers and airmen in Louisiana and more than 1,500 in Mississippi.

McKinley also helped the Homeland Security Department through a record number of disaster declarations and responses in 2011, she said, and in the aftermath of the 2010 BP oil spill in the Gulf of Mexico.

“I think we can say with confidence that our nation’s disaster response capabilities have been tested and, thanks in part to the strong partnership with the Guard, our successes are evident,” Napolitano said.

Together, Homeland Security and the National Guard also have made significant progress along the nation’s southwest border, the secretary said. In 2010, she noted, President Barack Obama authorized the temporary deployment of up to 1,200 National Guard troops to the border.

In that effort, the secretary said, “General McKinley has been instrumental in helping efficiently allocate state-of-the-art capabilities and capacities to bolster our efforts there both on the ground and in the air.”

The men and woman of the National Guard have strengthened Homeland Security’s ability to secure the border and target illicit networks, drugs and weapons, and smuggling of people and money, she added.

“The results of these comprehensive and coordinated efforts have been striking,” Napolitano said, using border patrol apprehensions as an example.

Such apprehensions, a key indicator of illegal immigration, she said, “have decreased 53 percent in the last three years and are less than 20 percent of what they were at their peak.”

“Illegal immigration attempts into this country have not been this low since 1971, the secretary said. “I thank General McKinley, the National Guard and our partners in DOD’s Joint Task Force North for their help in these achievements.”

The partnership between her department and the Guard has never been stronger, she said, “and General McKinley deserves a lot of credit for that.”

Napolitano also congratulated Grass for receiving his fourth star and taking the helm as the 27th chief of the National Guard Bureau. “General Grass, we look forward to working with you,” she added.

Because of the joint work of the Department of Homeland Security and the Guard, the secretary said, “the American people are safer from threats and hazards of all types.”